What's the best way to identify strange hissing/chirping sound coming from engine?

[Jm2576]

I have a strange sound coming from my engine that I cant identify

I recently had a slight inconsistent idle so I cleaned the IAC valve. That helped with the idle, but a few miles down the road I got a P0171 code and at the same time I started hearing this strange noise. It sort of sounds like a chirping noise like a bad pully/belt, but also a sucking/blowing sound at the same time. the sound is not as loud near the belts. I'm not sure how to describe it. Its pretty loud and I can hear it from across the yard. It seems to be coming from the manifold area, but its hard for me to tell and you can hear it from anywhere in the engine area.

Since I recently messed with the IAC I wonder if it could be an air issue? I put a vacuum gauge on and I am getting good vacuum. Is 21 on the high side? I also sprayed some carb cleaner and didn't get any surges so I'm pretty sure its not a vacuum leak.

I took a short audio recording with my phone, but I am not able to upload it as the extension is not allowed. Anyone know how to upload an audio/video recording?

Even though I have the P0701 code, the engine runs very well. Just a strange noise.

Thanks

 

[rusty ol ranger]

PO701 is a trans code.

I would get a mechanic stethoscope and start poking around around the intake manifold area, IAC area, anywhere air gets sucked in

 

[Jm2576]

Sorry...typo. The engine code is P0171: bank 1 system too lean (I corrected my original post). I'll see about picking up a stethoscope